Multi-speed transmission

ABSTRACT

A transmission is provided having an input member, an output member, four planetary gear sets, a plurality of coupling members and a plurality of torque transmitting devices. Each of the planetary gear sets includes first, second and third members. The torque transmitting devices are clutches and brakes.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/949,597 filed on Jul. 13, 2007. The disclosure of the aboveapplication is incorporated herein by reference.

FIELD

The invention relates generally to a multiple speed transmission havinga plurality of planetary gear sets and a plurality of torquetransmitting devices and more particularly to a transmission having nineor more speeds, four planetary gear sets and a plurality of torquetransmitting devices.

BACKGROUND

The statements in this section merely provide background informationrelated to the present disclosure and may or may not constitute priorart.

A typical multiple speed transmission uses a combination of frictionclutches, planetary gear arrangements and fixed interconnections toachieve a plurality of gear ratios. The number and physical arrangementof the planetary gear sets, generally, are dictated by packaging, costand desired speed ratios.

While current transmissions achieve their intended purpose, the need fornew and improved transmission configurations which exhibit improvedperformance, especially from the standpoints of efficiency,responsiveness and smoothness and improved packaging, primarily reducedsize and weight, is essentially constant. Accordingly, there is a needfor an improved, cost-effective, compact multiple speed transmission.

SUMMARY

A transmission is provided having an input member, an output member,four planetary gear sets, a plurality of coupling members and aplurality of torque transmitting devices. Each of the planetary gearsets includes first, second and third members. The torque transmittingdevices are for example clutches and brakes.

An embodiment of the transmission includes an input member, an outputmember, first, second, third and fourth planetary gear sets each havingfirst, second and third members. A first interconnecting membercontinuously interconnects the first member of the first planetary gearset with the second member of the second planetary gear set, a secondinterconnecting member continuously interconnects the second member ofthe first planetary gear set with the third member of the thirdplanetary gear set, a third interconnecting member continuouslyinterconnects the third member of the first planetary gear set with thesecond member of the fourth planetary gear set, and a fourthinterconnecting member continuously interconnects the third member ofthe second planetary gear set and the second member of the thirdplanetary gear set. Six torque transmitting mechanisms are selectivelyengageable to interconnect one of the first, second, and third memberswith at least one of the first members, second members, third members,and a stationary element. The torque transmitting mechanisms areselectively engageable in combinations of at least three to establish atleast nine forward speed ratios and at least one reverse speed ratiobetween the input member and the output member.

In one aspect of the present invention, a first of the six torquetransmitting mechanisms is selectively engageable to interconnect atleast one of the first member of the first planetary gear set and thesecond member of the second planetary gear set with the first member ofthe third planetary gear set.

In another aspect of the present invention, a second of the six torquetransmitting mechanisms is selectively engageable to interconnect atleast one of the third member of the second planetary gear set and thesecond member of the third planetary gear set with at least one of theinput member and the first member of the fourth planetary gear set.

In yet another aspect of the present invention, a third of the sixtorque transmitting mechanisms is selectively engageable to interconnectat least one of the third member of the second planetary gear set andthe second member of the third planetary gear set with the third memberof the fourth planetary gear set.

In yet another aspect of the present invention, a fourth of the sixtorque transmitting mechanisms is selectively engageable to interconnectthe first member of the second planetary gear set and the stationaryelement.

In yet another aspect of the present invention, a fifth of the sixtorque transmitting mechanisms is selectively engageable to interconnectthe first member of the third planetary gear set with the stationaryelement.

In yet another aspect of the present invention, a sixth of the sixtorque transmitting mechanisms is selectively engageable to interconnectat least one of the second member of the first planetary gear set andthe third member of the third planetary gear set with the stationaryelement.

In yet another aspect of the present invention, the first members aresun gears, the second members are carrier members, and the third membersare ring gears.

In yet another aspect of the present invention, the input member iscontinuously interconnected with the first member of the fourthplanetary gear set and wherein the output member is continuouslyinterconnected with at least one of the second member of the fourthplanetary gear set and the third member of the first planetary gear set.

In yet another aspect of the present invention, three of the torquetransmitting mechanisms are brakes and three of the torque transmittingmechanisms are clutches.

In yet another aspect of the present invention, the stationary elementis a transmission housing.

Another embodiment of the transmission of the present invention includesan input member, an output member, first, second, third and fourthplanetary gear sets each having first, second and third members, whereinthe input member is continuously interconnected with the first member ofthe fourth planetary gear set and wherein the output member iscontinuously interconnected with at least one of the second member ofthe fourth planetary gear set and the third member of the firstplanetary gear set. A first interconnecting member continuouslyinterconnects the first member of the first planetary gear set with thesecond member of the second planetary gear set, a second interconnectingmember continuously interconnects the second member of the firstplanetary gear set with the third member of the third planetary gearset, a third interconnecting member continuously interconnects the thirdmember of the first planetary gear set with the second member of thefourth planetary gear set, and a fourth interconnecting membercontinuously interconnects the third member of the second planetary gearset and the second member of the third planetary gear set. A firsttorque transmitting mechanism is selectively engageable to interconnectat least one of the first member of the first planetary gear set and thesecond member of the second planetary gear set with the first member ofthe third planetary gear set. A second torque transmitting mechanism isselectively engageable to interconnect at least one of the third memberof the second planetary gear set and the second member of the thirdplanetary gear set with at least one of the input member and the firstmember of the fourth planetary gear set. A third torque transmittingmechanism is selectively engageable to interconnect at least one of thethird member of the second planetary gear set and the second member ofthe third planetary gear set with the third member of the fourthplanetary gear set. A fourth torque transmitting mechanism isselectively engageable to interconnect the first member of the secondplanetary gear set and a stationary element. A fifth torque transmittingmechanism is selectively engageable to interconnect the first member ofthe third planetary gear set with the stationary element. A sixth torquetransmitting mechanism is selectively engageable to interconnect atleast one of the second member of the first planetary gear set and thethird member of the third planetary gear set with the stationaryelement. The torque transmitting mechanisms are selectively engageablein combinations of at least three to establish at least nine forwardspeed ratios and at least one reverse speed ratio between the inputmember and the output member.

In one aspect of the present invention, the first members are sun gears,the second members are carrier members, and the third members are ringgears.

In another aspect of the present invention, the stationary element is atransmission housing.

Another embodiment of the transmission of the present invention includesan input member, an output member, first, second, third and fourthplanetary gear sets each having a sun gear, a carrier member, and a ringgear, wherein the input member is continuously interconnected with thesun gear of the fourth planetary gear set and wherein the output memberis continuously interconnected with at least one of the carrier memberof the fourth planetary gear set and the ring gear of the firstplanetary gear set. A first interconnecting member continuouslyinterconnects the sun gear of the first planetary gear set with thecarrier member of the second planetary gear set, a secondinterconnecting member continuously interconnects the carrier member ofthe first planetary gear set with the ring gear of the third planetarygear set, a third interconnecting member continuously interconnects thering gear of the first planetary gear set with the carrier member of thefourth planetary gear set, and a fourth interconnecting membercontinuously interconnects the ring gear of the second planetary gearset and the carrier member of the third planetary gear set. A firsttorque transmitting mechanism is selectively engageable to interconnectat least one of the sun gear of the first planetary gear set and thecarrier member of the second planetary gear set with the sun gear of thethird planetary gear set. A second torque transmitting mechanism isselectively engageable to interconnect at least one of the ring gear ofthe second planetary gear set and the carrier member of the thirdplanetary gear set with at least one of the input member and the sungear of the fourth planetary gear set. A third torque transmittingmechanism is selectively engageable to interconnect at least one of thering gear of the second planetary gear set and the carrier member of thethird planetary gear set with the ring gear of the fourth planetary gearset. A fourth torque transmitting mechanism is selectively engageable tointerconnect the sun gear of the second planetary gear set and astationary element. A fifth torque transmitting mechanism is selectivelyengageable to interconnect the sun gear of the third planetary gear setwith the stationary element. A sixth torque transmitting mechanism isselectively engageable to interconnect at least one of the carriermember of the first planetary gear set and the ring gear of the thirdplanetary gear set with the stationary element. The torque transmittingmechanisms are selectively engageable in combinations of at least threeto establish at least nine forward speed ratios and at least one reversespeed ratio between the input member and the output member.

In one aspect of the present invention, the stationary element is atransmission housing.

Further objects, aspects and advantages of the present invention willbecome apparent by reference to the following description and appendeddrawings wherein like reference numbers refer to the same component,element or feature.

DRAWINGS

The drawings described herein are for illustration purposes only and arenot intended to limit the scope of the present disclosure in any way.

FIG. 1 is a lever diagram of an embodiment of a nine speed transmissionaccording to the present invention;

FIG. 2 is a diagrammatic view of an embodiment of a nine speedtransmission according to the present invention; and

FIG. 3 is a truth table presenting the state of engagement of thevarious torque transmitting elements in each of the available forwardand reverse speeds or gear ratios of the transmission illustrated inFIGS. 1 and 2.

DETAILED DESCRIPTION

The following description is merely exemplary in nature and is notintended to limit the present disclosure, application, or uses.

At the outset, it should be appreciated that the embodiments of the ninespeed automatic transmission of the present invention have anarrangement of permanent mechanical connections between the elements ofthe four planetary gear sets. A first component or element of a firstplanetary gear set is permanently coupled to a second component orelement of a fourth planetary gear set. A second component or element ofthe first planetary gear set is permanently coupled to a first componentor element of a third planetary gear set. A third component or elementof a first planetary gear set is permanently coupled to a secondcomponent or element of a second planetary gear set. A first componentor element of a second planetary gear set is permanently coupled to asecond component or element of a third planetary gear set.

Referring now to FIG. 1, an embodiment of a nine speed transmission 10is illustrated in a lever diagram format. A lever diagram is a schematicrepresentation of the components of a mechanical device such as anautomatic transmission. Each individual lever represents a planetarygear set wherein the three basic mechanical components of the planetarygear set are each represented by a node. Therefore, a single levercontains three nodes: one for the sun gear, one for the planet gearcarrier, and one for the ring gear. The relative length between thenodes of each lever can be used to represent the ring-to-sun ratio ofeach respective gear set. These lever ratios, in turn, are used to varythe gear ratios of the transmission in order to achieve appropriateratios and ratio progression. Mechanical couplings or interconnectionsbetween the nodes of the various planetary gear sets are illustrated bythin, horizontal lines and torque transmitting devices such as clutchesand brakes are presented as interleaved fingers. If the device is abrake, one set of the fingers is grounded. Further explanation of theformat, purpose and use of lever diagrams can be found in SAE Paper810102, “The Lever Analogy: A New Tool in Transmission Analysis” byBenford and Leising which is hereby fully incorporated by reference.

The transmission 10 includes an input shaft or member 12, a firstplanetary gear set 14 having three nodes: a first node 14A, a secondnode 14B and a third node 14C, a second planetary gear set 16 havingthree nodes: a first node 16A, a second node 16B and a third node 16C, athird planetary gear set 18 having three nodes: a first node 18A, asecond node 18B and a third node 18C, a fourth planetary gear set 20having three nodes: a first node 20A, a second node 20B and a third node20C and an output shaft or member 22.

The input shaft or member 12 is coupled to the third node 20C of thefourth planetary gear set 20. The output shaft or member 22 is coupledto the second node 20B of the fourth planetary gear set 20. The firstnode 14A of the first planetary gear set 14 is coupled to the secondnode 20B of the fourth planetary gear set 20. The second node 14B of thefirst planetary gear set 14 is coupled to the first node 18A of thethird planetary gear set 18. The third node 14C of the first planetarygear set 14 is coupled to the second node 16B of the second planetarygear set 16. The first node 16A of the second planetary gear set 16 iscoupled to the second node 18B of the third planetary gear set 18.

A first clutch 26 selectively connects the second node 16B of the secondplanetary gear set 16 to the third node 18C of the third planetary gearset 18. A second clutch 28 selectively connects the second node 18B ofthe third planetary gear set 18 to the third node 20C of the fourthplanetary gear set 20 and to input shaft or member 12. A third clutch 30selectively connects the second node 18B of the third planetary gear set18 to the first node 20A of the fourth planetary gear set 20. A firstbrake 32 selectively connects the third node 16C of the second planetarygear set 16 to a ground or a transmission housing 50. A second brake 34selectively connects the third node 18C of the third planetary gear set18 to a ground or a transmission housing 50. A third brake 36selectively connects the second node 14B of the first planetary gear set14 to a ground or a transmission housing 50.

Referring now to FIG. 2, a stick diagram presents a schematic layout ofthe embodiment of the nine speed transmission 10 according to thepresent invention. In FIG. 2, the numbering from the lever diagram ofFIG. 1 is carried over. The clutches, brakes and couplings arecorrespondingly presented whereas the nodes of the planetary gear setsnow appear as components of planetary gear sets such as sun gears, ringgears, planet gears and planet gear carriers.

For example, the planetary gear set 14 includes a sun gear member 14C, aplanet gear carrier member 14B supports a set of planet gears 14D and aring gear member 14A. The sun gear member 14C is connected for commonrotation with a first shaft or interconnecting member 42. The ring gearmember 14A is connected for common rotation with output shaft or member22. The planet gear carrier member 14B is connected for common rotationwith a second shaft or interconnecting member 44 and a third shaft orinterconnecting member 46. The planet gears 14D are each configured tointermesh with both the ring gear member 14A and the sun gear member14C.

The input shaft or member 12 is preferably continuously connected to anengine (not shown) or to a turbine of a torque converter (not shown).The output shaft or member 22 is preferably continuously connected withthe final drive unit or transfer case (not shown).

The planetary gear set 16 includes a sun gear member 16C, a ring gearmember 16A and a planet carrier member 16B that rotatably supports a setof planet gears 16D. The sun gear member 16C is connected for commonrotation with a fourth shaft or interconnecting member 48. The ring gearmember 16A is connected for common rotation with a fifth shaft orinterconnecting member 52. The planet carrier member 16B is connectedfor common rotation with the first shaft or interconnecting member 42and a sixth shaft or interconnecting member 54. The planet gears 16D areeach configured to intermesh with both sun gear member 16C and ring gearmember 16A.

The planetary gear set 18 includes a sun gear member 18C, a ring gearmember 18A and a planet carrier member 18B that rotatably supports a setof planet gears 18D. The sun gear member 18C is connected for commonrotation with a seventh shaft or interconnecting member 56. The ringgear member 18A is connected for common rotation with the third shaft orinterconnecting member 46. The planet carrier member 18B is connectedfor common rotation with the fifth shaft or interconnecting member 52and with an eighth shaft or interconnecting member 58. The planet gears18D are each configured to intermesh with both the sun gear member 18Cand the ring gear member 18A.

The planetary gear set 20 includes a sun gear member 20C, a planetcarrier member 20B that rotatably supports a set of planet gears 20D,and a ring gear member 20A. The sun gear member 20C is connected forcommon rotation with input shaft or member 12. The planet carrier member20B is connected for common rotation with output shaft or member 22. Thering gear member 20A is connected for common rotation with a ninth shaftor interconnecting member 60. The planet gears 20D are each configuredto intermesh with both the ring gear member 20A and sun gear member 20C.

The torque-transmitting mechanisms or clutches 26, 28, 30 and brakes 32,34 and 36 allow for selective interconnection of the shafts orinterconnecting members, members of the planetary gear sets and thehousing 50. For example, the first clutch 26 is selectively engageableto connect the sixth shaft or interconnecting member 54 to the seventhshaft or interconnecting member 56. The second clutch 28 is selectivelyengageable to connect the input shaft or member 12 to the eighth shaftor interconnecting member 58. The third clutch 30 is selectivelyengageable to connect the eighth shaft or interconnecting member 58 tothe ninth shaft or interconnecting member 60. The first brake 32 isselectively engageable to connect sun gear member 16C via fourth shaftor interconnecting member 48 to ground, a stationary element ortransmission housing 50 to restrict rotation of sun gear member 16Crelative to transmission housing 50. The second brake 34 is selectivelyengageable to connect sun gear member 18C via seventh shaft orinterconnecting member 56 to ground, stationary element, or transmissionhousing 50 to restrict rotation of sun gear member 18C relative totransmission housing 50. The third brake 36 is selectively engageable toconnect planet carrier member 14B and ring gear member 18A via secondshaft or interconnecting member 44 and third shaft or interconnectingmember 46 to ground, a stationary element or transmission housing 50 torestrict rotation of planet carrier member 14B and ring gear member 18Arelative to transmission housing 50.

In the present embodiment, the third brake 36 is larger than clutches26, 28, 30 and brakes 32, 34. For example, the third brake 36 hasincreased diameter friction plates or a greater number of frictionplates thus providing additional functional friction surface area thanthe clutches 26, 28, 30 and brakes 32, 34. The larger brake 36 allowsfor increased torque transmitting capacity, shorter engagement time, andimproved wear characteristics. However, the present inventioncontemplates that other embodiments have clutches and brakes 26, 28, 30,32, 34, and 36 of different sizes without departing from the scope ofthe present invention.

Referring now to FIGS. 2 and 3, the operation of the embodiment of thenine speed transmission 10 will be described. It will be appreciatedthat transmission 10 is capable of transmitting torque from the inputshaft or member 12 to the output shaft or member 22 in at least nineforward speed or torque ratios and at least one reverse speed or torqueratio with a triple overdrive. Each forward and reverse speed or torqueratio is attained by engagement of one or more of thetorque-transmitting mechanisms (i.e. first clutch 26, second clutch 28,third clutch 30, first brake 32, second brake 34 and third brake 36), aswill be explained below. FIG. 3 is a truth table presenting the variouscombinations of torque-transmitting mechanisms that are activated orengaged to achieve the various gear states. Actual numerical gear ratiosof the various gear states are also presented although it should beappreciated that these numerical values are exemplary only and that theymay be adjusted over significant ranges to accommodate variousapplications and operational criteria of the transmission 10. An exampleof the gear ratios that may be obtained using the embodiments of thepresent invention are also shown in FIG. 3. Of course, other gear ratiosare achievable depending on the gear diameter, gear teeth count and gearconfiguration selected.

To establish reverse gear, the second clutch 28, the first brake 32 andthe third brake 36 are engaged or activated. The second clutch 28connects the input shaft or member 12 to the eighth shaft orinterconnecting member 58. The first brake 32 connects sun gear member16C via fourth shaft or interconnecting member 48 to ground, astationary element or transmission housing 50 to restrict rotation ofsun gear member 16C relative to transmission housing 50. The third brake36 connects planet carrier member 14B and ring gear member 18A viasecond shaft or interconnecting member 44 and third shaft orinterconnecting member 46 to ground, a stationary element, ortransmission housing 50 to restrict rotation of planet carrier member14B and ring gear member 18A relative to transmission housing 50.Likewise, the nine forward ratios are achieved through differentcombinations of clutch and brake engagement, as shown in FIG. 3.

It will be appreciated that the foregoing explanation of operation andgear states of the nine speed transmission 10 assumes, first of all,that all the clutches not specifically referenced in a given gear stateare inactive or disengaged and, second of all, that during gear shifts,i.e., changes of gear state, between at least adjacent gear states, aclutch or brake engaged or activated in both gear states will remainengaged or activated.

The description of the invention is merely exemplary in nature andvariations that do not depart from the gist of the invention areintended to be within the scope of the invention. Such variations arenot to be regarded as a departure from the spirit and scope of theinvention.

1. A transmission comprising: an input member; an output member; first,second, third and fourth planetary gear sets each having first, secondand third members; a first interconnecting member continuouslyinterconnecting the first member of the first planetary gear set withthe second member of the second planetary gear set; a secondinterconnecting member continuously interconnecting the second member ofthe first planetary gear set with the third member of the thirdplanetary gear set; a third interconnecting member continuouslyinterconnecting the third member of the first planetary gear set withthe second member of the fourth planetary gear set; a fourthinterconnecting member continuously interconnecting the third member ofthe second planetary gear set with the second member of the thirdplanetary gear set; and six torque transmitting mechanisms selectivelyengageable to interconnect one of the first, second, and third memberswith at least one of the first members, second members, third members,and a stationary element, and wherein the torque transmitting mechanismsare selectively engageable in combinations of at least three toestablish at least nine forward speed ratios and at least one reversespeed ratio between the input member and the output member.
 2. Thetransmission of claim 1 wherein a first of the six torque transmittingmechanisms is selectively engageable to interconnect at least one of thefirst member of the first planetary gear set and the second member ofthe second planetary gear set with the first member of the thirdplanetary gear set.
 3. The transmission of claim 2 wherein a second ofthe six torque transmitting mechanisms is selectively engageable tointerconnect at least one of the third member of the second planetarygear set and the second member of the third planetary gear set with atleast one of the input member and the first member of the fourthplanetary gear set.
 4. The transmission of claim 3 wherein a third ofthe six torque transmitting mechanisms is selectively engageable tointerconnect at least one of the third member of the second planetarygear set and the second member of the third planetary gear set with thethird member of the fourth planetary gear set.
 5. The transmission ofclaim 4 wherein a fourth of the six torque transmitting mechanisms isselectively engageable to interconnect the first member of the secondplanetary gear set with the stationary element.
 6. The transmission ofclaim 5 wherein a fifth of the six torque transmitting mechanisms isselectively engageable to interconnect the first member of the thirdplanetary gear set with the stationary element.
 7. The transmission ofclaim 6 wherein a sixth of the six torque transmitting mechanisms isselectively engageable to interconnect at least one of the second memberof the first planetary gear set and the third member of the thirdplanetary gear set with the stationary element.
 8. The transmission ofclaim 1 wherein the first members are sun gears, the second members arecarrier members, and the third members are ring gears.
 9. Thetransmission of claim 1 wherein the input member is continuouslyinterconnected with the first member of the fourth planetary gear setand wherein the output member is continuously interconnected with atleast one of the second member of the fourth planetary gear set and thethird member of the first planetary gear set.
 10. The transmission ofclaim 1 wherein three of the torque transmitting mechanisms are brakesand three of the torque transmitting mechanisms are clutches.
 11. Thetransmission of claim 1 wherein the stationary element is a transmissionhousing.
 12. A transmission comprising: an input member; an outputmember; first, second, third and fourth planetary gear sets each havingfirst, second and third members, wherein the input member iscontinuously interconnected with the first member of the fourthplanetary gear set and wherein the output member is continuouslyinterconnected with at least one of the second member of the fourthplanetary gear set and the third member of the first planetary gear set;a first interconnecting member continuously interconnecting the firstmember of the first planetary gear set with the second member of thesecond planetary gear set; a second interconnecting member continuouslyinterconnecting the second member of the first planetary gear set withthe third member of the third planetary gear set; a thirdinterconnecting member continuously interconnecting the third member ofthe first planetary gear set with the second member of the fourthplanetary gear set; a fourth interconnecting member continuouslyinterconnecting the third member of the second planetary gear set withthe second member of the third planetary gear set; a first torquetransmitting mechanism selectively engageable to interconnect at leastone of the first member of the first planetary gear set and the secondmember of the second planetary gear set with the first member of thethird planetary gear set; a second torque transmitting mechanismselectively engageable to interconnect at least one of the third memberof the second planetary gear set and the second member of the thirdplanetary gear set with at least one of the input member and the firstmember of the fourth planetary gear set; a third torque transmittingmechanism selectively engageable to interconnect at least one of thethird member of the second planetary gear set and the second member ofthe third planetary gear set with the third member of the fourthplanetary gear set; a fourth torque transmitting mechanism selectivelyengageable to interconnect the first member of the second planetary gearset with a stationary element; a fifth torque transmitting mechanismselectively engageable to interconnect the first member of the thirdplanetary gear set with the stationary element; and a sixth torquetransmitting mechanism selectively engageable to interconnectinterconnect at least one of the second member of the first planetarygear set and the third member of the third planetary gear set with thestationary element, and wherein the torque transmitting mechanisms areselectively engageable in combinations of at least three to establish atleast nine forward speed ratios and at least one reverse speed ratiobetween the input member and the output member.
 13. The transmission ofclaim 12 wherein the first members are sun gears, the second members arecarrier members, and the third members are ring gears.
 14. Thetransmission of claim 12 wherein the stationary element is atransmission housing.
 15. A transmission comprising: an input member; anoutput member; first, second, third and fourth planetary gear sets eachhaving a sun gear, a carrier member, and a ring gear, wherein the inputmember is continuously interconnected with the sun gear of the fourthplanetary gear set and wherein the output member is continuouslyinterconnected with at least one of the carrier member of the fourthplanetary gear set and the ring gear of the first planetary gear set; afirst interconnecting member continuously interconnecting the sun gearof the first planetary gear set with the carrier member of the secondplanetary gear set; a second interconnecting member continuouslyinterconnecting the carrier member of the first planetary gear set withthe ring gear of the third planetary gear set; a third interconnectingmember continuously interconnecting the ring gear of the first planetarygear set with the carrier member of the fourth planetary gear set; afourth interconnecting member continuously interconnecting the ring gearof the second planetary gear set with the carrier member of the thirdplanetary gear set; a first torque transmitting mechanism selectivelyengageable to interconnect at least one of the sun gear of the firstplanetary gear set and the carrier member of the second planetary gearset with the sun gear of the third planetary gear set; a second torquetransmitting mechanism selectively engageable to interconnect at leastone of the ring gear of the second planetary gear set and the carriermember of the third planetary gear set with at least one of the inputmember and the sun gear of the fourth planetary gear set; a third torquetransmitting mechanism selectively engageable to interconnect at leastone of the ring gear of the second planetary gear set and the carriermember of the third planetary gear set with the ring gear of the fourthplanetary gear set; a fourth torque transmitting mechanism selectivelyengageable to interconnect the sun gear of the second planetary gear setwith a stationary element; a fifth torque transmitting mechanismselectively engageable to interconnect the sun gear of the thirdplanetary gear set with the stationary element; and a sixth torquetransmitting mechanism selectively engageable to interconnect at leastone of the carrier member of the first planetary gear set and the ringgear of the third planetary gear set with the stationary element, andwherein the torque transmitting mechanisms are selectively engageable incombinations of at least three to establish at least nine forward speedratios and at least one reverse speed ratio between the input member andthe output member.
 16. The transmission of claim 15 wherein thestationary element is a transmission housing.